1. Field of the Invention
The present invention relates to a magnetic memory device having a magnetic line in which information is recorded in each magnetic domain partitioned by domain walls, and a write/read method of the same.
2. Description of the Related Art
Recently, current-driven domain wall motion is reportedly observed in a thin magnetic line having a submicron width (e.g., non-patent reference 1), and magnetic shift registers capable of domain wall motion by using this effect are proposed (e.g., patent references 1 and 2, and non-patent reference 2). Each of these proposals implements a magnetic memory device having a structure similar to that of a magnetic tape by moving domain walls by an electric current with use of a magnetic line divided into a plurality of magnetic domains. The capacity of such a magnetic memory is now demanded to be increased by, e.g., raising the density of cells in a magnetic shift register.
[Patent reference 1] U.S. Pat. No. 6,834,005
[Patent reference 2] U.S.P. Publication No. 2004/0252538
[Non-patent reference 1] A. Yamaguchi et al., Phys Rev. Lett 92, 077205 (2004)
[Non-patent reference 2] Nikkei Electronics, No. 14, March 2005, pp. 26-27